Therapeutic lamp



April 3, 1934. R. B. WITHROW 1,953,206

THERAPEUTIC LAMP Filed Jan. 14, 1929 2 Sheets-Sheet l 2 INVEN TOR.

A TTORNE Y.

April 3, 1934.

R. B. WITHROW THERAPEUTIC LAMP Filed Jan. 14, 1929 2 Sheets-Sheet 2 A TTORNEY.

Patented Apr. 3, 1934 UNITED STATES PATENT OFFICE 1 Claim.

My invention relates to therapeutic lamps of the flaming arc type.

Theprinciple employed by me in the productionof an arc is the following, viz: that if two carbon electrodes are mounted in spaced parallel position and connected to the terminals of a suitable electric circuit, and the electrodes are then tilted so that their ends will approach, a spark will form first at the most contiguous positions on "the electrodes, and. when the electrodes are moved back to parallelism the spark will then travel down to the ends of the electrodes and there form a flaming are extending out from the tips of the electrodes and curvingback from one to the other. Parallel electrodes for formation of a. flaming are have been employed in maintaining an are, but the method employed in setting up the arc is to connect the tips of the parallel electrodes by some external means.

It is the object of my invention to provide a lamp having a plurality of stationary electrodes with a similar number of electrodes mounted in a movable support which may be tilted so as to cause the ends of the stationary electrodes to be approached by the ends of the movable elec-,

trodes, and to thereby cause a plurality of flaming arcs to be formed, the current passing normally down one stationary electrode back through a movable electrode, then returning 3o qthrough a movable electrode and returning through a stationary electrode and so on throughout the series. While in its simplest form I provide one pair of stationary electrodes and one pair of movable electrodes, as the invention say-is described, it. will be apparent that multiple series of movable and stationary electrodes may be combined in a similar manner.

The very simple way of striking an are between parallel electrodes of tipping one against the other and then moving them apart to substantial "parallelism, which I employ, permits of a foolproof and sturdy construction. The two electrodes when an arc is struck draw the are out to the tips of the electrodes, where itremains until 5 the electrodes are quite fully consumed.

It is an object of my invention to provide a simple manual adjustment for both moving the electrodes into such position that an arc will be formed, and for setting the electrodes so that they will remain sufiiciently far apart throughout most of their length as not to form a spark gap.

and still have their ends sufiiciently close together to allow the flaming arc to be formed.

It is a further specific object of my construcggtion to have the wires through which current is supplied to the electrodes connected only to stationary parts of the apparatus so that there will be no tendency for the wires to become loosened by contact with moving parts.

A still further object is the provision of a casing for supporting the electrodes which will accurately retain the electrodes in properly aligned position, and so proportioned that when electrodes are in position there can be no metal to metal contact between the supports.

By producing electrode slots of V shape or semi-oval shape, and holding the electrodes in the slots by means of springs, I provide for a snug grip on the electrodes, and thus enforce a desired parallelism as well as assure good contact.

The above and other objects to which reference will be made in the ensuing disclosure I accomplish by that certain combination and arrangement of parts of which I have shown a preferred embodiment.

Referring to the drawings:

Figure 1 is a side elevation with tion of the lamp assembly.

Figure 2 is a plan view of the top of the lamp with the reflector removed to more clearly illustrate the construction.

Figure 3 is a perspective view of the electrode holdersf Figure 4 is a perspective view of the movable holder with the retaining clips removed.

Figure 5 is a sectional view taken along the lines 55 in Figure 3.

The resistance unit generally indicated at 1 is formed with a casing 2 having a fabricated or woven wire cylindrical shell 3 extending between the upper head 4 and a supporting base 5. The electric wires to the lamp may be introduced into the upper head through an opening 6. One wire passes to the resistance coils forming the unit mounted on an asbestos support 7 and the other '95 extends up through a flexible hollow tube 8 which is mounted also in the top head. The connection of the wires will be described later.

At the top of the flexible tubing there is formed a circular plate 9 through which screws 10 secure the reflector 11 and an insulative mounting plate 12. The upper and fixed electrodes 13 are mounted in angular slots 14 in the sides of two brass blocks 15, 15a which are set apart on the mounting plate 12 and thus are insulated one from the other. The electrodes are held in position within the slots by spring clips 16, 16a which are mounted in the blocks with screws 17. The'electric wires through which the current is suitably parts in secstepped down are connected one to the block 15 no I and the other to the other spaced block 15a, as indicated at 15b, 150, so that until the current passes through the complementary movable electrodes, down one and back the other, no arc will be formed, and when it is thus formed it will be double and will be moved magnetically to the tips of the electrodes where it will burn from core to core.

The lower or movable electrodes 18 are mounted in a sold metallic block 18a which is pivotally mounted in a frame member 19 which in turn is secured on the insulative plate 12. As the lower block supporting the lower electrodes which are mounted in angular slots 20 in the sides of the block 18 must be movable, the mounting for the block 18 on the frame member 19 is by the pivot screws 21. The lower electrodes are also supported in the grooves 20 by spring clips 22 in a manner similar to that in which the upper electrodes are retained. The grooves 14 and 20 are of V shape, or may be semi-oval, with the same result. When electrodes are in place in the grooves, they are large enough to prevent the blocks from contacting with each other.

The method of mounting the electrodes has many advantages. In the first place, the springs are so placed that only a slight deflection is neces sary to accommodate the electrodes. This makes for long life. The springs will give sufliciently so that if one pair of electrodes is slightly bent and comes into contact before the other pair during the strik ng of the arc, this pair can rise somewhat from the grooves, thus permitting the other pair to be brought into contact. The springs will then bring the spring electrodes back to position. The electrode supports being smaller than the electrodes prevents the supports from coming into contact when the electrodes are short. The use of a slot which does not fit the electrodes but rather establishes two lines of contact, assures proper seating of the electrodes, avoids looseness, and enforces an accurate position of the electrodes.

For adjusting the position of the lower block carrying the electrodes, I have provided a bar 23 which is preferably attached to an internally threaded bushing 24 in the block 18 but which may be screwed directly into a threaded hole in the block without danger of causing a short circuit. A boss 25 is formed on the circular plate 12 through which an adjustment screw 26 is extended which bears against the bar 23. At the end of the bar I have also provided an insulated handle 2'? to permit the adjustment of the movable electrodes without danger of short circuiting.

It will be noted that the arrangement is such that the handle is depressed to t p the lower electrodes into contact with the upper. The natural or gravity position of the movable block is its open position in which the handle engages the adjustment screw.

The operation of the lamp will be apparent. The person who is to take a light treatment turns on the switch controlling the current to the lamp and then by pressing down on the handle 27, causes the tips of the lower pair of electrodes to approach the tips of the upper electrodes. As soon as a spark forms the operator releases the operating handle which permits the lower electrodes to move by gravity to arcing position substantially parallel to the upper electrodes. The arcs travel to the ends of the electrodes and form a pair of flaming arcs between the cores of the complementary electrodes. If the gap between the electrodes becomes too wide, by turning down the adjustment screw 26 the gap may be diminished and the flaming are kept at its full intensity.

While I have shown only one preferred embodiment other modifications will occur to those skilled in the art, but insofar as such modifications utilize the principles involved, I consider them within the scope of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent. is:

In an arc lamp, pairs of electrodes, one pair being adjustable to bring coacting electrodes of the pairs into parallelism and spring tongue clamps holding the respective electrodes, the coacting electrodes having parts projecting toward each other from within their respective clamps, precluding a short circuit directly from one clamp to the other when the parts of the electrodes projecting from the clamps have been consumed.

ROBERT B. WITHROW. 

